Three dimensional (3D) printing systems are in rapidly increasing use for purposes such as prototyping and manufacturing. One type of 3D printer utilizes an inkjet printhead to selectively deposit a material to form a three dimensional (3D) article of manufacture. In some embodiments the 3D printer utilizes phase change or wax based inks.
The inks are provided to the 3D printer via the installation of ink containers or cartridges. One challenge is to accurately track an amount of ink remaining in a cartridge. Non-contact methods are preferred but can lose accuracy with certain ink formulations.